Helicopter aircraft



M y 1933- B. NAGLER ET AL HELICOPTER AIRCRAFT Filed-Dec. L 1931 Z SheetS-Sheet 1 May 1933- s. NAGLER ET AL 1,909,845 HELICOPTER AIRCRAFT Filed Dec. 16, 1931 2 Sheets-Sheet 2 =60 from the engine driven ball Patented May 16, 1933 UNITED STATES ammo mama AND moor. mrnna, or vrnmu, aus'rara immcorrna arncm'r Application fled December 18, 1981, Serial No. 581,381, and in Austria December 18, 1980.

This invention relates to a helicopter aircraft in whi'chthe individual blades of the lifting screw are rotatable about their individual axes, and as a whole, as well .as

6 during their rotation, can be glven vary ng angles of incidence or setting so that the 11fting action can be varied as a whole as well as made different at different points of the circle of revolution, the points in the said 1 circle of greatest or smallest angle of incidence being variable at will. 7

The present invention relates to the mechanical and constructive features of such an aircraft. 7

The construction of the screw shaft offers substantial difiiculties as in addition to the Ezeat torque, it has to take up also very high nding moments. The invention eliminates these difliculties so by providing a bearing of a large diameter, one of the ball race rings of which is rigidly secured to the aircraft frame whilst the other ball race, driven from the engine, is used as I the base for' acing the lifting-screw boss or 28 hub, and for racing the blade arms.

Preferably, the bracing of the lifting screw hub or boss is effected bymeans of conically convergin struts mounted on the engine driven ba race ring or by means of a com- 30 plete cone surface. a

In order to ensure uniform bracmg of all the blade arms, the said bracing is effected by means of a strut of ad'ustable length mounted on the blade hub or ss in its axial :8 direction, to the free end of which are secured the bracing wires leading to the blade arms.

This method of bracing makes possible a construction in which'the arms of the liftin screw blades are mounted with inner en so that to dismantle the lifting-screw,

it is merely necessary to loosen the strainer wires by shortenin the bracing strut to such an extent as to enafiile the inner end pins of 4 thekblade arms to be pulledout of the bearing soc ets.

In order to make the bracin independentof the rotary-setti of the bla es' about their individual axes, ,t e bracin wires leading aring ring as ment relatively to the said axis.

"projecting from the non-rotating ball bearing a.

ferred to will be, more clearly understood 40 Big: in bearing sockets in the lifting screw- Flgure 2 is a side elevation on a reduced PATENT oFFicE well as those from the above mentioned bracing strut end, to the blade arms, ma be made to engage with sleeves freely rotata le on the blade arms but prevented from moving axially thereon. A substantial difference from the well known constructions will be found also in the mechanical arangement or device for the variation of the angle of setting of the lifting screw blades, which comprises a ring shaped ball bearing, co-axial with the lifting screw and capable of bothbodily adjustment in the axial direction, and of tilting adjust- One ball race ring engages with the adjusting control members, and the other ball race ring enga es with the members which effect the angu ar adi'ustment of the blades.

t is thus possible to mount both members with their respective ball race by simple pivot points and at these points any constantly slid'-. mg or rolling members are avoided, as the re ative movement of rotation between the adjusting control members and the blade adjusting members takes place ,through the relative turning of the two ball bearing rings. For modifying the inclination of the pla e of rotation of the said ball bearing relat vely to the lifting screw axis, there 1s provided according to the invention a controllever so or handle which can be moved bodil with the ball bearing in the direction of the ifting screw axis, and turned in every direction, and one end of which engages with a member race in the geometrical axis of the ball bearing or close to the same. a p

The features of the invention above refrom the following description of the accompanying drawings.

In these drawings,

Figure 1 is a side view of a scheme of con.- struction of helicopter aircraft accordin' to the invention, with certain portions bnfixen away to reduce the size of the drawings.

scale, with modified means for preventing rotation of the body of the aircraft during flight. 1 9

In the aircraft body 1 is mounted in a fixedmanner the large diameterball bearing race or ring 2. The second ball race or ring 3 rotatable in the same, has bevel wheel teeth 2 4 with which meshes the bevel pinion 6 driven by the motor or engine 5. Into the transm ssion shaft is inserted a free-wheel coupling 7 which, on the engine being stopped, ensures free rotatability of the lifting screw.

The inner ball race ring 3, which owing to:

its large diameter is very suitable for taking up great turning or lifting'forces, is used as. the base for the bracing and supporting =of the lifting-screw boss 8, situated in the geometrical axis of the ring, and of the blade arms. 9. This boss 8 is braced against the ring 3 by means of struts 10. In place of the struts 10, a solid cone surface of sheet metal of the like might be used, fixed to the ring 3 with its apex supporting the boss 8. The boss 8 has approximately vradially arranged bearing sockets in which are mounted the inner bearing pins of the blade arms 9. On the boss 8 ismounted in its geometrical axis of rotation, a bracing strut 11 which. can be lengthened or shortened by means of opposite.

screw-threads by means of-the turnbuckle 12. The bracing of the blades is eflected by means of strainer wires 13 attached to the ring-3, and ofstrainer wires 14 attached to theupper end of the strut 11. All the strainer wires are carried to sleeves 15-which are,

. gether merely b lengthening or shortening the strut 11. ysuitably shortening the strut 11, it .can be withdrawn from its seat on the boss-8, thus slackening the bracing wires 13. and 14, so that the blade arms 9 can be, withdrawn from their hearing sockets in the boss 8. Instead of mounting the sleeve in a rotatable manneron .its blade arm, it might be rigidly secured to it, as the strainer wires, *as they engage practically with only one common point 0 the blade arm,.can' yield suificiently to the slight variation of length when the blades are turned. 1

The blade arms'9 carry cranks 16 which are linked by means of rods 17 to the outer ball race ring 18 of a ball hearing which is arranged centrally in relation to the ball hearing 2, 3 andthe'inner ball-'racering 19 of which. is supported in such a manner that it is vertically adjustable and can be inclined in every. direction." To ensure that the 'ball race ring 18 shall participate in the rotation of the ball race ring 3, the latter is provided with guides 20 with which pins 21 of'the rin 18 engage. The ring 19 and therefore the whole ball bearing, may be moved parallel tothe general axis through the boss 8 by the supports 22 by means of the control lever. arrangement ,23,, 2A.v On; the, su ports 22 is articulated the, Gammon ilni'Yel'sag'joint frame 25 on which the ring 19 is trunnioned.

OtherIforms of universal joint mightbe substituted 'for that shown, such as some convenient arrangement of a ball and socket joint. The, tilting of the ring 19 is eiiected by means of the control lever 26' which ismounted on the supports 22 so as to be vertically adjustable therewith, and the free end'of the said lever 26 engages with a socket28 of thestirrup 27 the up'per'endsot which areconfl nected to the ring 19. The socket 28 isarranged exactly or approximately 'inthe.

geometrical axis of-the ball;bearing-18, 19., Theraising and lowering of the ball bearing 18, 19 by means of thecontrol' lever 24 pro.--.

duces a simultaneous variation of the angle of setting of all-the lifting screw blades, whilst the inclination .of the bearing "by means of the control handle or lever 26 pro! duces variation of the angle of incidence ot the blades during their rotation.

The free wheel coupling 7 is intended to 9 enable the'lifting screwto rotate freely in, the event of the engine being stopped. During the glidingof the aircraft, theli-fting screw will be driven by the air current rising relatively to it. ing screw can then beutilized for taking up the shock of landing by moving the blades into a position producing a lift.

The 'controlsurfaces or planes 29 mountedon the body, which are substantially vertical and can be inclined. from that position to either side, are struck by the downward air current from the lifting screw, and produceing screw, it is known to arr'ange on the aircraft body upright'tail planes. 29 (Figure 3)- which. canbe set at different angles to the vertical, and are str'uck by the air current from the lifting screw, and in deflecting it, are subject to a, counter. torque which prevents the aircraft body from rotating.- The invention utilizes .ior thesame purpose the Magnus? efl'ect, for which there is provided a substantially horizontal rotor 30 (Figure 2-) driven from the engine, and pref erably with a speed substantially proportional to that of the lifting screw. This has the-advantage that'with the "increase of the speed of rotation 'ojf the 'liftingscrew' and of the torque increasing with--it,the-Mag-' 10 The energy stored in the liftmounted above t e lifting nus effect or the counter torque will also automatically increase.

We claim: 1. A helicopter aircraft comprising a lift- 5 ing screw with blades and blade arms and a hub for supporting the inner ends of the said arms, a ball bearing of large diameter, one ball race ring of which is fixed to the aircraft frame while the other ring is rotatable and forms the base-for supporting and bracing the lifting screw' hub by a pyramidally converging structure attached on the one hand a to the said rotatable bearing ring and on the other hand to the lifting screw hub.

2. Aircraft according to claim 1, wherein the said converging, structure consists of" pyramidally conver ing struts.

3. Aircraft accor ing to claim 1, wherein the said converging structure consists of a geometrical axis of rotation, and bracing wires betweenthe upper end of the said strut and the blade arms and between the blade arms and the said rotatable ball race ring.

6. Aircraft according to claim 1, comprising a bracing strut of ad ustable length mounted above the lifting screw hub in its geometrical axis of rotation, and bracing wires between the upper end of the said strut .and the blade arms and between the blade arms and the said rotatableball race ring, and wherein the inner ends of the arms of u the lifting screw blades are mounted b withdrawable bearing pins-in bearing soc ets in the. lifting screw hub, whereby; the lifting screw can be dismounted b shortening the ad'ustable strut to loosen t e' bracing wires ciently to enable thebearing pins of the blade arms to-be withdrawn from the bearin sockets. Y 4

Aircraft according to claim 1, comprising a bracin strut of adjustable length screw hub in its geometrical axis of sitatlon, bracing wires between the upper en of the said strut and the blade arms and between the blade arms and the said rotatable ball race ring, and

sleeves mounted upon the blade arms bymeans preventing them from longitudinal v movement thereon, the said bracing wires being connected to the said sleeves.

i 8. Aircraft according. to claim '1, com prising a bracing strut of adjustable length closed hollow pyramidal structure with its.

gitudinal movement on the said arms while permitting the, said arms to rotate in the said sleeves, the said bracing wires being connected to the said sleeves.

9. Aircraft according to claim 1, having means for producing variation of the, angle of incidence of the lifting screw blades, the

said means comprising a second ball bearing one race of which is connected with the rotatable ring of the first mentioned bearing by' means'causing it to rotate therewith, and also connected with the blade arms by means causing variation of the inclination of the blades by up or down movement of thesaid second bearing, and means connected with the other ring of the said second ball hearing to effect up and down adjustment of the said bearing. v i

10. Aircraft according to claim 1, having means for producing variation of the an le .of incidence of the lifting screw blades, t e

said means comprising a second ball bearing onerace of which is connected with the ro-- tatable ring of the first mentioned bearing by means causing it to rotate therewith, and a s 0 connected with the blade arms by means causing variation of the inclination of the blades by up or down movement of the said second bearing, means connected with the other ring of the said second ball bearing to effect up and down adjustment of the said bearing, and means also connected with the said other ring of said second bearing for varying its inclination to effect differential variation of the angle of incidence .of the blades at different positions in the circular path of rotation.

11. Aircraft according to claim 1, comprising a horizontally dis osed rotor mounted thereon in the path 0 the down current of the lifting screw to provide a Magnus effect producing a torque counter-acting the torque of the lifting screw.

a "drivin motor for drivin the airscrew through t 'e rotatable ring of t e ball bearing,-

and a free-wheeljco'upling between the said 115 12. Aircraft according to cla'ini'l, having 

